The present invention is directed to materials and processes of producing materials. More specifically, the present invention is directed to polyurethane foams and pre-mixes and processes of producing polyurethane foams and pre-mixes.
Polyurethane foams are used in a variety of products. Such products are present in the automotive industry, the housing industry, other building and manufacturing industries, and elsewhere. Many of such known polyurethane foam products are produced by reacting a polyisocyanate with a polyol in the presence of additives.
One such additive is chlorofluorocarbon, commonly known as CFC. CFC is used as a blowing agent which vaporizes as a result of a reaction exotherm causing a polymerizing mass to form into foam. CFCs suffer from a drawback that they deplete ozone in the stratosphere, thus creating environmental concerns.
Use of water as a blowing agent involves generation of CO2 from the reaction of the water and the polyisocyanate. Due to the environmental hazard of using CFC, use of water as the blowing agent has becoming more prevalent. However, use of water as the blowing agent presents additional challenges.
Tertiary amine catalysts are known to be used to accelerate blowing when the blowing agent is water. The tertiary amine catalysts selectively promote the blowing or gelling in the production of the polyurethane foam product. If too much of the blowing tertiary amine catalyst is included in the process, then CO2 will bubble out of the polyurethane foam product and the structure of the polyurethane foam product will collapse, for example, resulting in broken or poorly defined cell structure.
Use of tertiary amine catalysts in forming polyurethane foam products has also been undesirable due to the hazards of tertiary amines. Tertiary amines are malodorous and highly volatile. In addition, they can have safety and toxicity concerns. Thus, it is desirable for little or no emission of tertiary amines to occur when used. To achieve this, known tertiary amine catalysts can include isocyanate-reactive groups which are capable of immobilizing the amine catalysts in a polyurethane polymer. However, the resulting products can have undesirable properties, such as substantially degrading under accelerated ageing with hot humidity. Alternatively, using low vapor-pressure, high-molecular weight amine catalysts can require usage of high amounts of catalyst, thereby being cost prohibitive in manufacturing processes.
Several known processes include use of additives to produce polyurethane products. For example, U.S. Pat. No. 4,007,140, which is hereby incorporated by reference in its entirety, discloses N,N′-bis(3-dimethylaminopropyl)urea as a low odor catalyst. U.S. Pat. Nos. 4,338,408 and 4,433,170, which are each incorporated by reference in their entirety, disclose additives structurally related to bis(dimethylamino)ethyl ether as a blowing catalyst. U.S. Pat. Nos. 5,508,314, 5,559,161, and 5,633,293, which are each incorporated by reference in their entirety, disclose an additive having a high amount of amine catalysts containing secondary alcohols to balance promotion of active hydrogen-isocyanate reactions and reaction of isocyanates with the additive. The additives disclosed in the above-referenced patents do not improve humid aged properties.
U.S. Pat. No. 5,859,079, which is hereby incorporated by reference in its entirety, discloses an additive with N,N′-bis(3-dimethylaminopropyl)urea and 3-dimethylaminopropylurea at a predetermined ratio to control flowability, air-flow, and force to crush properties of the polyurethane product. U.S. Pat. No. 6,114,403, which is hereby incorporated by reference in its entirety, discloses an additive with N,N′bis(3-dimethylaminopropyl)urea and 3-dimethylaminopropylurea at a predetermined ratio to control flowability and percent of open cell content for rigid polyurethane foam products. The additives disclosed in the above-referenced patents do not improve humid aged properties.
Known additives are used for producing water-blown flexible polyurethane foam products. U.S. Pat. No. 6,201,033, which is hereby incorporated by reference in its entirety, discloses an additive that includes tertiary amino alkyl urea and/or bis(tertiary amino alkyl)urea in combination with either a tertiary amine gelling catalyst or a tertiary amine blowing catalyst. U.S. Pat. No. 6,232,356, which is hereby incorporated by reference in its entirety, discloses an additive that includes tertiary amino alkyl urea and/or bis(tertiary amino alkyl)urea in combination with either a gelling catalyst or a blowing catalyst to improve physical properties of the produced product. The additives disclosed in the above-referenced patents do not improve humid aged properties.
U.S. Pat. No. 6,858,654, which is hereby incorporated by reference in its entirety, discloses additives for catalyzing a polyurethane foaming reaction that includes a gelling catalyst and a blowing catalysts selected such that the resulting polyurethane foam product has a low level of volatile and/or malodorous material. The identified additives are tertiary aminoalkyl substituted primary or secondary amines, bis(aminoalkyl)ethers having aklanol moieties, primary amine moieties, or unreido moieties derived from primary amine moieties. The additives disclosed in the above-referenced patent do not improve humid aged properties.
WO/2004/113,410, which is hereby incorporated by reference in its entirety, discloses an additive containing a quaternary ammonium alkoxide moiety and a partially or totally neutralized tertiary amine group with an acid compound. The additive disclosed in WO/2004/113,410 does not improve humid aged properties.
U.S. Pat. Nos. 7,666,919 and 7,615,580, which are each incorporated by reference in their entirety disclose methods involving an additive with a non-emissive catalyst in the presence of an ester alcohol or carbamate to increase humid aged deterioration properties. The additive is used at a high concentration (for example, greater than 1.0 parts per one hundred parts polyol, commonly referred to as pphp) to produce polyurethane with the properties, thereby being cost-prohibitive. In general, the additive disclosed in the above-referenced patents and the other above-described additives suffer from the drawback of being unable to produce polyurethane foam products having desirable performance properties for humid aged conditions in an economical manner.
A polyurethane foam production process, pre-mix, formulation, and product that do not suffer from one or more of the above drawbacks would be desirable in the art.